Introduction to Introduction to Computational Computational

LinguisticsLinguistics

Dr. Radhika MamidiDr. Radhika MamidiENG 270ENG 270

Lecture 1

What is Linguistics?What is Linguistics? The scientific study of human languageThe scientific study of human language

Aim is to establish a theory by studying nature Aim is to establish a theory by studying nature of a language and by applying this established of a language and by applying this established theory to describe other languagestheory to describe other languages

Descriptive study not prescriptiveDescriptive study not prescriptive

Speech activity - speaker, hearer, setting, Speech activity - speaker, hearer, setting, code, medium; plus topic, contextual code, medium; plus topic, contextual knowledge, abiding social norms, knowledge, abiding social norms, communicative competencecommunicative competence

Applied LinguisticsApplied LinguisticsSubfields / Inter-disciplinary fields:Subfields / Inter-disciplinary fields:

Sociolinguistics Sociolinguistics Lexicography Lexicography Stylistics Stylistics Computational LinguisticsComputational Linguistics Semiotics Semiotics PsycholinguisticsPsycholinguisticsLanguage Teaching/Learning Language Teaching/Learning Translation Studies Translation Studies Anthropological LinguisticsAnthropological Linguistics

Note: Now ‘Applied Linguistics’ is associated with Note: Now ‘Applied Linguistics’ is associated with Lg teaching.Lg teaching.

What is What is Computational Computational linguistics? linguistics?

“ “Computational linguistics is an Computational linguistics is an interdisciplinary field dealing interdisciplinary field dealing with the statistical and logical with the statistical and logical modeling of natural language modeling of natural language from a computational from a computational perspectiveperspective.”.”

Goal of Computational Goal of Computational linguistics linguistics

To make the computers understand To make the computers understand human language.human language.

To use technology to build language To use technology to build language tools.tools.

Use computers to process or produce Use computers to process or produce human language.human language.

We want to communicate with We want to communicate with computers in the language we speak!computers in the language we speak!

WhyWhy Computers should talk Computers should talk with us?with us?

The main obstacle in the interaction The main obstacle in the interaction between human and computer is between human and computer is communication problem. communication problem.

Computers do not understand our language Computers do not understand our language and learning computer language is difficult.and learning computer language is difficult.

Computer language do not match the Computer language do not match the structure of human thought. structure of human thought.

The use of human language in computer The use of human language in computer applications will benefit the userapplications will benefit the user..

Most interesting CL Most interesting CL application: application: chatbotchatbot

A A chatterbotchatterbot (or chatbot) is a type of (or chatbot) is a type of conversational agent.conversational agent.

It is a computer program designed to It is a computer program designed to simulate an intelligent conversation simulate an intelligent conversation with one or more human users via with one or more human users via auditory or textual methods.auditory or textual methods.

It is a computer program with artificial It is a computer program with artificial intelligence to talk to people through intelligence to talk to people through voices or typed words. voices or typed words.

Computational Linguistics

Computer Science

Cognitive Science

Philosophy

Mathematics

Psychology

Linguistics

Computational linguistics is an interdisciplinary field. It takes input from different fields.

Relation of CL to Other Relation of CL to Other DisciplinesDisciplines

Artificial IntelligenceArtificial Intelligence (notions of representation, search) (notions of representation, search)

Machine LearningMachine Learning (probabilistic or statistical techniques) (probabilistic or statistical techniques)

Human Computer InteractionHuman Computer Interaction (HCI) (HCI)

LinguisticsLinguistics (Syntax, Semantics etc.) (Syntax, Semantics etc.)

Information Retrieval Information Retrieval

Philosophy of languagePhilosophy of language (formal logic) (formal logic)

Electrical EngineeringElectrical Engineering (Optical Character Recognition) (Optical Character Recognition)

Psychology Psychology (insight into learning of linguistic constructions)(insight into learning of linguistic constructions)

Computational LinguisticsComputational Linguisticsis closely related to…is closely related to…

Natural Language TechnologyNatural Language Technology Natural Language EngineeringNatural Language Engineering Natural Language ProcessingNatural Language Processing Artificial IntelligenceArtificial Intelligence

Some Applications of Some Applications of Computational LinguisticsComputational Linguistics

Spelling and Grammar Checkers Spelling and Grammar Checkers Screen readers for the blindScreen readers for the blind Machine readable DictionariesMachine readable Dictionaries Machine Translation SystemsMachine Translation Systems Question-Answering SystemsQuestion-Answering Systems Information RetrievalInformation Retrieval Information ExtractionInformation Extraction Automatic SummarizationAutomatic Summarization

Example Application- Search EngineExample Application- Search Engine

Example Application- Spelling Example Application- Spelling CheckerChecker

Example Application- Grammar Example Application- Grammar CheckerChecker

Example Application- Question AnsweringExample Application- Question Answering

Example Application- Machine TranslationExample Application- Machine Translation

Careers for Computational Careers for Computational linguistslinguists

AcademiaAcademia Research and Higher educationResearch and Higher education Teaching in IT or EnglishTeaching in IT or English

IndustryIndustry Companies that work in fields like:Companies that work in fields like: speech technology, information extraction, machine speech technology, information extraction, machine

translation, automatic summarization, etc. translation, automatic summarization, etc. - Microsoft, Google, HP Labs, Xerox Research are some Microsoft, Google, HP Labs, Xerox Research are some

major companies developing language tools.major companies developing language tools.- Information Technology departments of BanksInformation Technology departments of Banks- Web designing that needs language and computer Web designing that needs language and computer

knowledgeknowledge

Likely jobs for Computational Likely jobs for Computational linguistslinguists

Software EngineersSoftware Engineers Researchers in Machine TranslationResearchers in Machine Translation Teachers of Computer Teachers of Computer

Science/Linguistics in schoolsScience/Linguistics in schools Linguistic database analyzersLinguistic database analyzers Designers of mono/bi-lingual Designers of mono/bi-lingual

dictionariesdictionaries Speech technologistsSpeech technologists Teaching or Research AssistantsTeaching or Research Assistants

Getting a job in language Getting a job in language technologytechnology

Best candidate has:Best candidate has: Advanced degree in linguistics Advanced degree in linguistics Coursework or major in computational Coursework or major in computational

linguistics or computer science linguistics or computer science Knowledge of foreign language(s) Knowledge of foreign language(s) Computer scripting or programming Computer scripting or programming

skills skills Work or internship in industry Work or internship in industry

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Some companies that hire Some companies that hire computational linguistscomputational linguists

CL Research - tools for developing lexical databasesCL Research - tools for developing lexical databaseshttp://http://www.clres.comwww.clres.com//

Comverse - speech technology for computers and internetComverse - speech technology for computers and internethttp://http://www.comverse.comwww.comverse.com

CycorpCycorphttp://http://www.cyc.comwww.cyc.com

IBM - dictation software for English and other languagesIBM - dictation software for English and other languageshttp://www-4.ibm.com/software/speech/http://www-4.ibm.com/software/speech/

Language Intelligence - a linguistic software companyLanguage Intelligence - a linguistic software companyhttp://http://www.languageintelligence.comwww.languageintelligence.com

Lingsoft - a linguistic software companyLingsoft - a linguistic software companyhttp://http://www.lingsoft.fiwww.lingsoft.fi//

Scansoft - speech recognition systemsScansoft - speech recognition systemshttp://http://www.scansoft.comwww.scansoft.com

Soliloquy - natural language understanding softwareSoliloquy - natural language understanding softwarehttp://http://www.soliloquy.comwww.soliloquy.com

Microsoft - software for dictation and text-to-speechMicrosoft - software for dictation and text-to-speechhttp://www.microsoft.comhttp://www.microsoft.com

Exercise 1 Exercise 1 Write down what you have understood by Write down what you have understood by

‘Computational Linguistics’?‘Computational Linguistics’? Try the different applications mentioned Try the different applications mentioned

and write down your observations.and write down your observations. Do you think the tools are useful to us?Do you think the tools are useful to us?

Submit your work before the next class.Submit your work before the next class.

Exercise 2Exercise 2 Observe how the Observe how the spelling and grammar checkerspelling and grammar checker

on your pc works. Give 5 errors that were pointed on your pc works. Give 5 errors that were pointed out by each tool.out by each tool.

Practice giving the right keywords to search for a Practice giving the right keywords to search for a document using document using Google or YahooGoogle or Yahoo. Give the results.. Give the results.

Look for different Look for different chatbotschatbots, make a list of the urls, , make a list of the urls, talk to them and judge which one is the best one.talk to them and judge which one is the best one.

To DoTo DoWrite down your observations and submit them as Write down your observations and submit them as

soon as you are done.soon as you are done.

Assignment 1Assignment 1Due date: After 2 weeksDue date: After 2 weeks

Write short essays [minimum 8-10 Write short essays [minimum 8-10 sentences] on the following topics:sentences] on the following topics:

Spelling and grammar checkersSpelling and grammar checkers Your favorite search engineYour favorite search engine You and a chatbotYou and a chatbot

You have to include examples, urls, references, You have to include examples, urls, references, sample data etc. wherever necessary.sample data etc. wherever necessary.

Marks will be deducted if any kind of plagiarism Marks will be deducted if any kind of plagiarism is found.is found.